Extrusion dies are attached to a last barrel of an extruder to form a processed material into desired products. Accordingly, the die should have a structure, clamping arrangements or other such means for attachment to the extruder.
There are many types of extrusion dies for extruders that form products of differing shapes and geometries. A sheet extrusion die takes a processed material, for example, a fluid stream usually flowing in a pipe, and shapes it into a thin, wide, uniform flat sheet of uniform-flowing fluids. A film extrusion die takes a fluid stream and shapes it into a thin, wide, uniform film. A stranding extrusion die takes a fluid stream and shapes it into a wide row of uniform-flowing strands. A profile extrusion die takes a fluid stream and shapes it into a complex and often multi-dimensional article, such as a door frame. These types of extrusion dies are discussed in the art.
An extruder die may comprise a screen pack, which can be provided in combination with a breaker plate. The screen pack is located at a predetermined position in or next to the extruder die to filter product as it passes through the extruder die or before the product has passed through the extruder die, and is retained in place by a clamping attachment arrangement. Preferably, the screenpack is located in the extruder die to filter the processed material as it passes through the extruder die. Screen packs in extruder dies must be periodically changed to ensure that their filtering is effective. Often the changing of the screen pack is long, laborious and time intensive process. Further, the changing of a screen pack often may cause considerable spillage, and accordingly resulting in large amounts of product waste.
There are several known clamping attachment arrangements available commercially to attach together an extruder die, screen packs, and an extruder. These clamping attachment arrangements are often cumbersome. Most clamping attachment arrangements are not positioned for an easy and expedited screen pack changing process, and are often inadequately arranged and positioned so as to cause considerable spillage and a waste of resources. Further, these clamping arrangements do not provide their own independent support and rely upon support from other external structures.
For example, one clamping arrangement comprises two collars, which bolt together at both ends. The collars however are not provided with their own separate support, and are generally hung from an overhead chain that renders the clamping arrangement awkward to manipulate and hard to use. Further, this type of support makes operation of the clamping arrangement potentially dangerous, which is undesirable. Other known clamping arrangements comprise complex two-bolt clamping arrangement designs. The two-bolt clamping arrangements are horizontally split, and attached to a flange of a last barrel of an extruder apparatus. When these clamping arrangements are opened, processed material from the extruder apparatus will often spill and drool onto the clamp mechanism, which of course is undesirable.
A vertically split one-bolt clamping arrangement design for an extruder die is also known, and is attached to a flange of an extruder's last barrel. This clamping arrangement design includes a pivot pin on a top portion and a bolt on the bottom to support the arrangement. The bolt is positioned in a location that is very difficult to access. Thus, product often falls onto the bolt, which is undesirable since it makes the arrangement more difficult to use.
Therefore, it is desirable to provide an extrusion die clamping assembly that permits for easy operation and quickchange of screen packs. It is also desirable to provide a mounting mechanism that allows a die and clamp to swing away from the extruder and attaches a mounting mechanism directly to the extruder so additional support structures are unnecessary. Further, it is desirable to provide a clamping arrangement that is small, light weight, and easy to use. Accordingly during a filter changing process, a minimum amount of spillage and reduced downtime are achieved to avoid large clean-ups and to conserve resources.